All of the Hearts players struck by the illness that led to the postponement of Tuesday's match in Inverness have reported for Thursday's training.
A bout of gastroenteritis left the Edinburgh club with "few fit players", with the game rescheduled for 12 April.
Aberdeen, 12 points ahead of third-placed Hearts, visit Tynecastle on Friday evening.
"The players are over the illness and they're ready to go," head coach Robbie Neilson told BBC Scotland.
"They've taken a couple of days, as expected.
"It was a 24 to 48 hour thing and when they run out tomorrow under the floodlights in front of a full house there will be no issue about energy."
|Hearts winger Sam Nicholson|
|"I'm happy to be rid of the virus. I've never experienced anything like it. We're getting the blame for it, the boys who were away with the Scotland U21s. I think I'll be fine but it's not until I get out there kicking a ball that I'll find out."|
Hearts closed their Riccarton training base on Tuesday and Wednesday to prevent the bug spreading further.
"We asked the players to go to their own gyms and do a bit of work themselves," explained Neilson.
"It's not the ideal preparation but it had to be done."
Hearts have a game in hand over Aberdeen and Neilson is confident that his team can overhaul the Dons if they get the better of Friday's contest.
"It's a huge game," he said. "Aberdeen are desperate to win to keep close to Celtic and we're desperate to win to keep close to Aberdeen.
"A draw doesn't do anybody any good.
"We play Aberdeen twice and we have a game in hand. If we win those, the gap is down to three points going into the split and it's going to be tight.
"Yes, Aberdeen are a very good team and expected to finish second, if they can't finish first, so it's up to us to try and nick that sport off them."
Callum Paterson has missed the last five matches with a shoulder injury but Neilson expects the full-back to return against Aberdeen.